Fig. 6

Endothelial-specific and ubiquitous Dll4 deregulation promotes equally hypoxia and apoptosis in Apc ^Min/+ tumors. a, b, d, e Immunofluorescence stainings of 20 μm (a, b) and 10 μm (d, e) cryosections of small (a, d) and large (b, e) intestinal tumors collected from Apc ^Min/+ endoDll4 ^-/-, Apc ^Min/+ ubiqDll4 ^-/- and control (CT) mice at 18 weeks of age. Scale bars = 100 μm. Representative images of staining density for PECAM-1 (in green) and HIF1α (in red) (a, b), and for TUNEL (in green) and PECAM-1 (in red) (d, e). The nuclei were counterstained with DAPI (in blue). c, f Graphic bars represent the relative (%) ± SEM small (SI) and large intestinal (LI) tumor hypoxia (c) and tumor apoptotic index (f) in the mice described above. One experiment with n = 6 per group and 6 fields per animal. *P < 0.05; **P < 0.01